EXTERNAL ELECTRIC-FIELD EFFECT ON THE PROPERTIES OF BLEUSTEIN-GULYAEVSURFACE ACOUSTIC-WAVES IN LITHIUM-NIOBATE AND STRONTIUM-TITANATE

The paper presents theoretical results for the effects of differently oriented external electric field on the velocity of Bleustein-Gulyaev surface acoustic waves (BG SAW) in lithium niobate and strontium titan ate for different mechanical crystal states. It has been revealed that the BG SAW is unstable towards external effects, i.e. that the electr ic field not only alters its velocity, but it also yields the wave dir ection displacement. It is shown that, unlike the Rayleigh wave, the B G SAW exhibits a wave localization depth which substantially depends o n the external effects. (C) 1998 Elsevier Science B.V.